A policeman stands atop Punjab University, keeping guard over a crowd of thousands attending funeral prayers for Muslim cleric Sarfraz Naeemi in Lahore June 13, 2009. Naeemi was attacked by a suicide bomber in his mosque complex after leading Friday prayers a day earlier. Pakistani warplanes struck a stronghold of Pakistani Taliban leader Baitullah Mehsud on Saturday in retaliation for the killing of the anti-Taliban cleric, the military said.

REUTERS/Adrees Latif

ISLAMABAD â€“ Pakistanâ€™s army launched airstrikes and ferried in tanks and artillery as it confirmed Tuesday that it was preparing a major offensive against insurgents in al-Qaida and the Talibanâ€™s safest haven along the Afghan border.

The highly anticipated military operation in South Waziristan is seen as a potential turning point in the yearslong and sometimes half-hearted fight against militancy in Pakistan. It could also help curb Taliban attacks on Western forces in neighboring Afghanistan. But the offensive in the lawless tribal region will also be the toughest yet for Pakistanâ€™s military, testing both its fighting capability and the governmentâ€™s will to see it through, analysts said. Pakistani army spokesman Maj. Gen. Athar Abbas said the military had received executive orders from the government to begin operations against Pakistani Taliban leader Baitullah Mehsud, whose base is in South Waziristan.

â€œThe necessary measures and steps which are part of a preliminary phase of the operation, the preparatory phase of the operation, that has commenced,â€ Abbas told a news conference.

But Information Minister Qamar Zaman Kaira stressed that the operation â€œhas not been officially started.â€

They declined to give more details, citing operational secrecy.

Convoys of military trucks carrying tanks and artillery were seen Tuesday in the towns of Dera Ismail Khan and Tank, near South Waziristan. Intelligence officials said they were part of the buildup for the operation against Mehsud.

In recent days, the military has shelled and launched airstrikes in both South Waziristan and neighboring Bannu, although so far there has not been large-scale fighting with the militants.

On Tuesday, the army shelled suspected militant hideouts in three villages in South Waziristan in response to attacks on two military checkpoints, and helicopter gunships targeted Mehsud hide-outs in the region, intelligence officials told The Associated Press.

One official called the attacks â€œsurgical strikesâ€ ahead of the main operation.

The officials spoke on condition of anonymity because they were not authorized to disclose information to the media.

The military buildup comes as the army says it is entering the final stages of a major operation against the Taliban in the northwestern Swat Valley, which has triggered a wave of retaliatory attacks by militants across Pakistan that have been blamed on Mehsud.

More than 100 people have died since late May in suicide bombings on targets including police and security buildings, mosques and a hotel catering to foreigners. The attacks have fueled anti-Taliban sentiment in Pakistan that in turn has emboldened the politically weak government of President Asif Ali Zardari.

A military assault in South Waziristan would likely trigger an escalation in the attacks â€” something the government is bracing for.

â€œThe risk of lives is there â€” we have to give sacrifices, we have to pay this price and the nation is ready to give this price to get rid of this menace,â€ Kaira said.

The slow start to the offensive may indicate the government is talking it up before launching it to allow civilians time to flee. The Swat offensive displaced more than 2 million people.

Thousands of residents have already fled Waziristan, local officials and refugees say, and are most are staying with extended family. Aid agencies have warned that the humanitarian crisis in Pakistanâ€™s northwest could worsen if fighting spreads in the tribal belt.

The armed forces may also need more time to mobilize for a full-scale battle in Waziristan, a hard-scrabble, mountainous area where well-armed tribes hold sway and the governmentâ€™s influence is minimal.

Many Taliban and al-Qaida militants fled to the region after the U.S.-led invasion that ousted the Taliban regime in Afghanistan after the Sept. 11 attacks on the United States. It remains a base for cross-border attacks on Western and Afghan forces and a training center for militants operating in both Afghanistan and Pakistan. South Waziristan is also a possible hiding place of al-Qaida leader Osama bin Laden and his deputy Ayman al-Zawahri.

Militants have had years to dig in and store arms and ammunition in bolt-holes that include concrete bunkers and tunnel networks, said Asad Munir, a retired brigadier and former intelligence chief for the tribal region.

Battle-hardened fighters from Afghanistan, Swat and elsewhere will rally to join the fight, he predicted.

â€œThis is going to be their final battlefield because the prominent leaders of al-Qaida, the Afghan Taliban, the local Taliban and our own terrorist jihadi organizations, they are all here,â€ Munir said. â€œThey will defend this place, which has acted as a sanctuary for them.â€

U.S. missiles fired from unmanned drones have repeatedly struck South Waziristan, most recently on Sunday, and militants would become far more vulnerable to airborne attacks if they are forced out of their strongholds by Pakistanâ€™s offensive. The military has launched repeated operations in the past, only to later back off as the government has pursued failed peace deals instead.

Abbas said Tuesday there were unconfirmed reports that al-Qaida-linked Uzbek militant leader Tahir Yuldash was injured in a Pakistani air force strike Sunday in South Waziristan. He gave no further details.

Yuldash leads the Islamic Movement of Uzbekistan and has survived numerous Pakistan military operations to trap him in the tribal regions.